How to deal with an annoying friend?

ok..umm. ive known this girl since gr.10 but lately, since last sat (feb 14), she's been getting on my nerves...we were hanging out with our other friend tasha and john and she was annoying us so much, like hitting us or even just trying to get attention...also, she calls my friend tasha and i all the time and not just once..if she can't get through, she'll call 3 times in a row on the cell and then home right after..it's too much and i was on reading week last week and so was she and she kept on calling & texting constantly but i needed my space to study..She called my home and my dad picked up the phone and said I was in brampton at my cousins' which I was and then she calls my cell right after...I don't know what to do and I've talked to tasha bout it and tasha says that she is too much for her as well sometimes...She's an only child too and ****, we're 20 so she needs to grow up..thanks for any answers!!!! =)